General exam question G0B05
Subelement G0, ELECTRICAL AND RF SAFETY· Group G0B
Which of the following conditions will cause a ground fault circuit interrupter (GFCI) to disconnect AC power?
- A.Current flowing from one or more of the hot wires to the neutral wire
- B.Current flowing from one or more of the hot wires directly to ground (correct answer)
- C.Overvoltage on the hot wires
- D.All these choices are correct
WhyA ground fault circuit interrupter disconnects AC power when current flows from one or more of the hot wires directly to ground. A GFCI continuously compares current flowing out on the hot conductor against current returning on the neutral, and it trips the instant it detects current escaping to ground instead of returning normally, exactly the fault condition that indicates a shock hazard, answer B. It isn't triggered by current simply moving between hot and neutral in the normal course of powering a load, and it doesn't respond to overvoltage conditions, that's a different protective device's job, so A, C, and D are wrong.
Published 2026-08-28 · Last updated 2026-08-28 · Question text is verbatim from the 2023-2027 NCVEC Element 3 pool (public domain); the explanation above is original writing, see our methodology.
Related questions
- G0B01Which wire or wires in a four-conductor 240 VAC circuit should be attached to fuses or circuit breakers?
- G0B02According to the National Electrical Code, what is the minimum wire size that may be used safely for wiring with a 20-ampere circuit breaker?
- G0B03Which size of fuse or circuit breaker would be appropriate to use with a circuit that uses AWG number 14 wiring?
- G0B04Where should the station’s lightning protection ground system be located?
- G0B06Which of the following is covered by the National Electrical Code?